Added multiple build types
Added 32 bit sram access to make zpu work
sram works, boots, keyboard works
Fixed PLL to more appropriate for PAL/NTSC with he 32MHz input clock. Should work now, although no ZPU yet!
replacing with pal/ntsc plls of correct input frequency
First cut of papilio duo support. NB: This does not work yet, notably PLL needs changing. Then sram needs wiring up to allow zpu to run.